Single post in F2P ZC User Complaints + No Money Spending Tips!!!
This is gonna be a bit long, bear with me '^^ If you want my direct, honest advice - sell summon items for ZC in your shop and keep the stock updated. People are always buying summons with ZC. You should also send scour teams out every hour to get boxes/credits. By the way, how many pokemon can you send scouring at once? Do you have 2 extra scour slots and 2 extra scour boosts? It's important to have those to get boxes more frequently.
My personal advice/experience
You can still be a free to play user and have the same benefits as everyone else! Credits are easy to get. Clicking pokemon, selling items (from your inventory or the market), selling pokemon, or offering paid services (dexing, rentals, etc.) can earn you some credits. There's also a list of tasks at the bottom of your "Party" page that you can complete for extra credits too! All of this to say that the Market can be your friend. Spend those credits in the Market to buy stuff that you'd usually buy with ZC (like Hypermode, Shiny Charms, Memory Stick) If getting ZC is the goal then you have to think about what people spend ZC for. (Look at other Trade Shops and see what sells well and what doesn't) Selling BoxBoxes, D/S/A/M pokemon, or Summon Items tend to bring in a decent amount of ZC! You'll have to make sure to keep up your stock, though (this keeps consistent customers). And now about your shop... I hate to be that guy but, maybe your shop isn't doing so well because you don't offer a ton of common services right now? More importantly, I see a lot of vacant tabs in there. It'll help your shop if you bulk your stock a little! ^^